RAW MATERIAL:1010
FINISH: BLACK/ZP/NICKEL PLATED
STANDARD: DIN1587
SAE J483
SIZE: M3-M30
#10-1”
GRADE: ISO 898-2 (CL.5)
SAE J995 (GR.2)
Our Cap Nuts, also known as Dome Nuts, are designed to provide both a secure fastening function and a finished, enclosed appearance. Unlike conventional open-ended hex nuts, the domed cap completely covers the exposed end of the bolt, helping protect the protruding thread from direct contact, contamination, and accidental snagging. This enclosed design makes Cap Nuts particularly suitable for applications where safety, appearance, thread protection, and clean assembly are important, including automotive components, machinery, furniture, equipment, decorative assemblies, electrical products, and general industrial applications. By covering the exposed bolt end, Cap Nuts can also create a cleaner finished surface, making them an attractive alternative to standard open nuts in visible assemblies.
Our Cap Nuts are manufactured from 1010 carbon steel, a commonly used material offering a practical combination of machinability, durability, and cost efficiency. The available mechanical property grade is ISO 898-2 Class 5 for metric applications and SAE J995 Grade 2 for inch-based applications. These grades position the product well for general-purpose mechanical fastening rather than specialized high-strength structural applications. As with any nut-and-bolt assembly, the nut grade should be properly matched with the corresponding bolt and selected according to the actual loading and service conditions of the application.
The defining feature of a Cap Nut is its closed dome-shaped top. Once installed, the cap covers the exposed portion of the mating bolt, reducing the possibility of the exposed thread becoming a snagging point or coming into direct contact with users, surrounding components, or other materials. At the same time, the enclosed structure helps shield the bolt end from dust, dirt, and other external contaminants. This makes Cap Nuts especially useful in assemblies where exposed threads would be undesirable from a safety, maintenance, or appearance perspective.
In addition to their functional benefits, Cap Nuts provide a more finished appearance than conventional hex nuts. The smooth domed top eliminates the visually exposed end of the bolt and creates a cleaner, more uniform fastening point. This makes them particularly valuable for visible mechanical assemblies, furniture hardware, equipment housings, automotive components, railings, fixtures, and products where the appearance of the finished fastening system matters. For manufacturers, using a Cap Nut can therefore combine a practical fastening function with a more refined final appearance without requiring a separate decorative cover.
Our Cap Nuts are manufactured according to recognized international standards, including DIN 1587 and SAE J483, supporting both metric and inch-based fastening requirements. This broad range allows customers to select suitable Cap Nuts for applications from relatively compact assemblies to larger general-purpose mechanical fastening systems.
DIN 1587
SAE J483
Metric: M3–M30
Inch: #10–1"
To accommodate different appearance and environmental requirements, our Cap Nuts are available in Black, Zinc Plated (ZP), and Nickel Plated finishes.
A practical solution for general industrial applications and assemblies where a dark surface appearance is preferred.
Enhanced corrosion protection for common indoor and moderately corrosive environments.
A distinctive metallic appearance and additional surface protection, suited to visible or decorative applications.
The combination of thread protection, enclosed construction, safety considerations, and finished appearance makes Cap Nuts suitable for a wide range of applications. They can be used on automotive parts, machinery, electrical equipment, furniture, fixtures, equipment panels, decorative structures, and general mechanical assemblies where the bolt end needs to be covered rather than left exposed. For applications where the primary requirement is maximum structural load capacity, a suitable conventional or heavy-duty nut may be more appropriate; however, where the fastening system also needs to address exposed-thread protection, user safety, contamination, and appearance, a Cap Nut offers a clear functional advantage.
With 1010 carbon steel construction, ISO 898-2 Class 5 and SAE J995 Grade 2 specifications, DIN 1587 and SAE J483 standards, M3–M30 and #10–1" sizes, and Black/ZP/Nickel Plated finishes, our Cap Nuts provide a flexible sourcing solution for manufacturers, distributors, equipment producers, and industrial buyers.
Whether the requirement is to protect exposed threads, improve assembly safety, create a cleaner finished appearance, or provide additional protection around the end of a bolt, our Cap Nuts combine functional protection with a professional finished look, making them a practical choice for both industrial and visible fastening applications.
